Heat 2 tablespoons of olive oil over medium heat in a large skillet. Add the chicken pieces, season with salt and pepper, and sauté for about 5-7 minutes until golden brown. Remove the chicken and set aside.

In the same skillet, add the diced onion and sliced mushrooms. Cook over medium heat for 5-6 minutes until browned and translucent.

Sprinkle 3 tablespoons of flour over the mixture, stirring well to combine and cook for 1-2 minutes.

Gradually pour in 2 cups of chicken broth while stirring continuously for 3-4 minutes until the sauce thickens slightly.

Reduce heat to low and stir in 1 cup of sour cream and 1 teaspoon of garlic powder. Mix thoroughly.

Return the chicken to the skillet and stir it into the sauce to coat. Heat through for an additional 2-3 minutes.

Serve over mashed potatoes or egg noodles, garnished with fresh parsley if desired.